| 1. |
- Andersson, Maria, 1975, et al.
(författare)
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Differential global gene expression response patterns of human endothelium exposed to shear stress and intraluminal pressure
- 2005
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Ingår i: J Vasc Res. - : S. Karger AG. - 1018-1172. ; 42:5, s. 441-52
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the global gene expression response of endothelium exposed to shear stress and intraluminal pressure and tested the hypothesis that the two biomechanical forces induce a differential gene expression response pattern. Intact living human conduit vessels (umbilical veins) were exposed to normal or high intraluminal pressure, or to low or high shear stress in combination with a physiological level of the other force in a unique vascular ex vivo perfusion system. Gene expression profiling was performed by the Affymetrix microarray technology on endothelial cells isolated from stimulated vessels. Biomechanical forces were found to regulate a very large number of genes in the vascular endothelium. In this study, 1,825 genes were responsive to mechanical forces, which corresponds to 17% of the expressed genes. Among pressure-responsive genes, 647 genes were upregulated and 519 genes were down regulated, and of shear stress-responsive genes, 133 genes were upregulated and 771 down regulated. The fraction of genes that responded to both pressure and shear stimulation was surprisingly low, only 13% of the regulated genes. Our results indicate that the two different stimuli induce distinct gene expression response patterns, which can also be observed when studying functional groups. Considering the low number of overlapping genes, we suggest that the endothelial cells can distinguish between shear stress and pressure stimulation.
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| 2. |
- Forte, A, et al.
(författare)
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c-Myc antisense oligonucleotides preserve smooth muscle differentiation and reduce negative remodelling following rat carotid arteriotomy
- 2005
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Ingår i: Journal of Vascular Research. - : S. Karger AG. - 1423-0135 .- 1018-1172. ; 42:3, s. 214-225
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The vascular biology of restenosis is complex and not fully understood, thus explaining the lack of effective therapy for its prevention in clinical settings. The role of c-Myc in arteriotomy-induced stenosis, smooth muscle cell (SMC) differentiation and apoptosis was investigated in rat carotids applying full phosphorothioate antisense ( AS) oligonucleotides (ODNs). Methods: Carotid arteries from WKY rats were submitted to arteriotomy and to local application of ODNs through pluronic gel. Apoptosis ( deoxynucleotidyl transferase-mediated dUTP nick end-labelling), SMC differentiation (SM22 immunofluorescence) and vessel morphology and morphometry ( image analysis) were determined 2, 5 and 30 days after injury, respectively. Results: AS ODNs induced a 60% decrease of target c-Myc mRNA 4 h after surgery in comparison to control sense ( S) and scrambled ODN-treated carotids (p < 0.05). A significant 37 and 50% decrease in SM22 protein in the media of S ODN-treated and untreated carotids was detected when compared to uninjured contralateral arteries (p < 0.05). This reduction in SM22 expression was prevented in AS ODN-treated carotids. Stenosis was mainly due to adventitial constrictive remodelling. Lumen area in AS ODN-treated carotids was 35% greater than in control arteries 30 days after surgery (p < 0.05). TUNEL assay revealed increased apoptosis in AS ODN-treated carotids (p < 0.05). Conclusions: c-Myc AS ODNs reduce arteriotomy-induced negative remodelling. This is accompanied by maintained SMC differentiation and greater apoptosis. The combination of reduced c-Myc-induced proliferation and increased apoptosis may thus underlie the less severe remodelling upon treatment with c-Myc mRNA AS ODN.
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| 3. |
- Gidlöf, Andreas C., et al.
(författare)
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Differences in retinol metabolism and proliferative response between neointimal and medial smooth muscle cells
- 2006
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Ingår i: Journal of Vascular Research. - : S. Karger AG. - 1018-1172 .- 1423-0135. ; 43:4, s. 392-398
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Tidskriftsartikel (refereegranskat)abstract
- Vascular disease is multifactorial and smooth muscle cells (SMCs) play a key role. Retinoids have been shown to influence many disease-promoting processes including proliferation and differentiation in the vessel wall. Phenotypic heterogeneity of vascular SMCs is a well-known phenomenon and phenotypic modulation of SMCs precedes intimal hyperplasia. The SMCs that constitute the intimal hyperplasia demonstrate a distinct phenotype and differ in gene expression compared to medial SMCs. Cellular retinol-binding protein-1 (CRBP-I), involved in retinoid metabolism, is highly expressed in intimal SMCs, indicating altered retinoid metabolism in this subset of cells. The aim of this study was to evaluate the metabolism of all-trans ROH (atROH), the circulating prohormone to active retinoids, in vascular SMCs of different phenotypes. The results show an increased uptake of atROH in intimal SMCs compared to medial SMCs as well as increased expression of the retinoid-metabolizing enzymes retinol clehydrogenase-5 and retinal dehydrogenase-1 and, in conjunction with this gene expression, increased production of all-trans retinoic acid (atRA). Furthermore, the retinoic acid-catabolizing enzyme CYP26A1 is expressed at higher levels in medial SMCs compared to intimal SMCs. Thus, both retinoid activation and deactivation processes are in operation. To analyze if the difference in ROH metabolism was also correlated to differences in the biological response to retinol, the effects of ROH on proliferation of SMCs with this phenotypic heterogeneity were studied. We found that intimal SMCs showed a dose- and time-dependent growth inhibition when treated with atROH in contrast to medial SMCs, in which atROH had a mitogenic effect. This study shows, for the first time, that (1) vascular SMCs are able to synthesize biologically active atRA from the prohormone atROH, (2) intimal SMCs have a higher capacity to internalize atROH and metabolize atROH into atRA compared to medial SMCs and (3) atROH inhibits growth of intimal SMCs, but induces medial SMC growth.
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| 4. |
- Goncalves, Isabel, et al.
(författare)
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Elastin- and Collagen-Rich Human Carotid Plaques Have Increased Levels of the Cysteine Protease Inhibitor Cystatin C.
- 2008
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Ingår i: Journal of Vascular Research. - : S. Karger AG. - 1423-0135 .- 1018-1172. ; 45:5, s. 395-401
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cystatin C is a major inhibitor of the elastin- and collagen-degrading cysteine proteases and may therefore have an important role in preserving atherosclerotic plaque stability. In this study we analyzed the associations between human carotid plaque cystatin C expression and the plaque content of collagen and elastin. Methods: Thirty-one plaques were removed by endarterectomy and homogenized. Cystatin C levels were analyzed by densitometry of Western blots and elastin and collagen levels were determined colorimetrically. Results: The plaque content of cystatin C correlated with total elastin (r = 0.58, p = 0.001) and collagen (r = 0.50, p = 0.004), as well as with cross-linked forms of elastin (r = 0.42, p = 0.022) and collagen (r = 0.52, p = 0.003). Immunohistochemical analysis demonstrated that cystatin C colocalized with elastin and collagen. No correlation was seen between cystatin C and the amount of degraded elastin or collagen in plaques. Conclusion: The positive correlation between cystatin C levels and collagen and elastin levels in plaques supports the notion that cystatin C plays an important role in maintaining atherosclerotic plaque stability. Copyright (c) 2008 S. Karger AG, Basel.
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| 5. |
- Jatta, Ken, et al.
(författare)
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Lipopolysaccharide-induced cytokine and chemokine expression in human carotid lesions
- 2005
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Ingår i: Journal of Vascular Research. - : S. Karger AG. - 1018-1172 .- 1423-0135. ; 42:3, s. 266-271
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Tidskriftsartikel (refereegranskat)abstract
- The release of cytokines and chemokines from activated immune-competent cells plays a crucial role in determining the pathology of the atherogenic progress. We investigated the effect of bacterial lipopolysaccharide (LPS) on cytokine/chemokine expression in carotid lesions and normal renal arteries. The lesions or renal arteries were incubated for 6 h at 37 degrees C in serum-free media treated with or without LPS. After LPS treatment, increased protein levels of IL-1beta, IL-6, IL-8, IL-10, TNF-alpha and MCP-1 were observed in the culture medium from the lesions measured with cytometric bead array. We were able to detect the induction of IL-1beta, IL-6, IL-8, IL-10, TNF-alpha and MCP-1 mRNA in the lesions after stimulation with LPS using real-time PCR. In renal arteries, LPS also induces mRNA expression of all chemokines and cytokines investigated with the exception of IL-6. However, LPS induces significantly higher levels of TNF-alpha, IL-1beta and IL-10 mRNA in lesions compared to renal arteries. The results suggest that infectious agents are capable of enhancing the production of cytokines/chemokines in an already ongoing inflammatory process such as in atherosclerosis, and that low levels of circulating LPS may affect the levels of pro-inflammatory cytokines much more in atherosclerotic vessels than in normal vessels and may contribute to the development of the atherosclerotic lesion.
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| 6. |
- Settergren, M, et al.
(författare)
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Endothelin-A receptor blockade increases nutritive skin capillary circulation in patients with type 2 diabetes and microangiopathy
- 2008
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Ingår i: Journal of vascular research. - : S. Karger AG. - 1423-0135 .- 1018-1172. ; 45:4, s. 295-302
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Tidskriftsartikel (refereegranskat)abstract
- <i>Aims:</i> Endothelin-1 levels are elevated in patients with type 2 diabetes mellitus and may contribute to impaired microvascular function. We investigated the effect of selective endothelin-A (ET<sub>A</sub>) receptor blockade (BQ123) on skin microcirculation in patients with type 2 diabetes and albuminuria. <i>Methods:</i> Ten type 2 diabetes patients and 8 non-diabetic controls were investigated. Nutritive skin capillary circulation, investigated by videophotometric capillaroscopy, and total skin microcirculation, assessed by laser Doppler fluxmetry (LDF), were studied during intra-arterial infusion of saline for 15 min, followed by BQ123 infusion for 60 min. <i>Results:</i> Following BQ123 infusion there was a significant increase in resting capillary blood cell velocity (CBV) in patients with type 2 diabetes from 0.24 (0.20–0.34) mm/s at baseline to 0.61 (0.46–0.88) mm/s at 60 min, but no significant change in the control subjects [0.55 (0.10–0.68) vs. 0.38 (0.13–0.88) mm/s; p < 0.005 for difference between groups]. Peak CBV following arterial occlusion and skin temperature increased significantly in the type 2 diabetes group but not in the control group during BQ123 infusion. There were no significant changes in LDF parameters during infusion of BQ123 in either group. <i>Conclusion:</i> ET<sub>A</sub> receptor blockade improves nutritive skin capillary circulation in patients with type 2 diabetes and microangiopathy.
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| 7. |
- Soehnlein, O, et al.
(författare)
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ACE inhibition lowers angiotensin-II-induced monocyte adhesion to HUVEC by reduction of p65 translocation and AT 1 expression
- 2005
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Ingår i: Journal of vascular research. - : S. Karger AG. - 1018-1172 .- 1423-0135. ; 42:5, s. 399-407
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Tidskriftsartikel (refereegranskat)abstract
- Angiotensin-converting enzyme (ACE) inhibitors interfere with several key events of vascular inflammation resulting in impressive reductions in coronary vascular events. However, in human arteries ACE inhibitors block the production of angiotensin II (AngII) incompletely because of the involvement of alternative pathways in local AngII formation. Therefore, our study concentrated on the presumed modulation by ACE inhibition of local AngII-mediated inflammatory actions by a mechanism independent of blockage of AngII formation. We analyzed the effect of the ACE inhibitor ramiprilat on AngII-dependent cell adhesion molecule (CAM) expression and adhesion of monocytic THP-1 cells to endothelial cells. AngII induced upregulation of P-selectin, VCAM-1 and ICAM-1 on endothelial cells via activation of AT1, which was correlated with enhanced THP-1 adhesion in flow chamber assays. Both enhanced adhesion and adhesion molecule expression were significantly reduced by pretreatment with ramiprilat. Ramiprilat reduced AT1 expression on endothelial cells and decreased the AngII-induced p65 translocation into the nucleus. Diminished AT1 expression and adhesion molecule expression in response to ramiprilat treatment were partially reversed after incubation with a bradykinin 2 receptor antagonist, suggesting that elevated bradykinin levels under ACE inhibition may be involved in the beneficial effect of ACE inhibitors. Thus, modulation of the local AngII system by ramiprilat may at least in part contribute to the benefits of ACE inhibition in the treatment of atherosclerotic diseases.
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| 8. |
- Tesselaar (Droog), Erik, et al.
(författare)
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A time–response model for analysis of drug transport and blood flow response during iontophoresis of acetylcholine and sodium nitroprusside
- 2009
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Ingår i: Journal of Vascular Research. - Basel, Switzerland : S. Karger. - 1018-1172 .- 1423-0135. ; 46:4, s. 270-277
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Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: The analysis of blood flow responses to iontophoresis of vasoactive drugs is often limited to evaluation of maximum responses. In this study, a time-response model is proposed for the blood flow responses to vasoactive drugs applied by iontophoresis. Methods: The microvascular bed is represented as a single compartment with a zero-order influx of the drugs from the electrode and a first-order clearance due to diffusion and blood flow. The blood flow response to the local drug dose is described using the Emax model. Results: The model accurately describes the blood flow responses to acetylcholine and sodium nitroprusside during a single iontophoretic current pulse. There is a significant clearance out of the microvascular bed during iontophoresis which depends on the type of drug administered. Conclusion: The model enables an accurate estimation of response parameters such as ED50 and maximum response, even if the true maximum blood flow is not obtained. The results suggest that due to clearance from the microvascular bed, the local drug dose during a single pulse of current is not linearly proportional to current strength multiplied by pulse duration.
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| 9. |
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| 10. |
- Wågsäter, Dick, et al.
(författare)
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Expression of IL-1β, IL-1 receptor type I and IL-1 receptor antagonist in human aortic smooth muscle cells : effects of all-trans-retinoic acid
- 2006
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Ingår i: Journal of Vascular Research. - : S. Karger AG. - 1018-1172 .- 1423-0135. ; 43:4, s. 377-382
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Tidskriftsartikel (refereegranskat)abstract
- The proinflammatory cytokine interleukin (IL)-1β and the IL-1 receptor antagonist are expressed by atherosclerotic plaques and may be linked to the development of atherosclerosis. Existing evidence shows that retinoids and their receptors are involved in inflammatory response and that they are found in atherosclerotic plaques. In all-trans-retinoic acid (atRA)-treated human aortic smooth muscle cells (AOSMC), significant increases in IL-1β levels were observed, compared with untreated cells. Examination of IL-1 receptor antagonist and IL-1 receptor type I levels did not show any difference between atRA-treated and -untreated AOSMC. The results show that atRA-treated AOSMC express both the precursor (33 kDa) and the active form (17 kDa) of the IL-1β protein. atRA-treated carotid lesions showed significantly elevated IL-1β mRNA levels (2.9 ± 2.33) compared with untreated lesions (2.0 ± 1.77; p < 0.05). These results support the role of atRA as a regulator of inflammation such as in atherosclerosis.
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